With Avent Anti-Colic Feeding Bottle, SCF821/12 make sure that your baby stays protected from any digestive issues while getting the right nutrition filled feed. Its anti-colic valve stops air from entering in to his stomach and only let's milk pass through. It only allows required amount of milk to enter into baby's tummy while reducing the chances of over-feeding or spit-ups. The soft silicone nipple gives comfortable feed without harming baby's delicate gums. It comes in variable teat sizes to suit to your baby's age.